Chronic back problems cause pain and disability for a large segment of the population. Frequently, the cause of back pain is traceable to diseased or degenerated disc material between adjacent vertebrae. When the disc material is diseased, the adjacent vertebrae may be inadequately supported, resulting in persistent pain. Surgical techniques have been developed to remove all or part of the diseased disc material and fuse the joint between adjacent vertebral bodies. Stabilization and/or arthrodesis of the intervertebral joint can reduce the pain associated with movement of a diseased intervertebral joint. Spinal fusion may be indicated to provide stabilization of the spinal column for a wide variety of spine disorders including, for example, structural deformity, traumatic instability, degenerative instability, post-resection iatrogenic instability, etc.
Generally, fusion techniques involve partial or complete removal of the diseased disc and implanting a vertebral implant or spacer between the adjacent vertebral bodies to facilitate new bone growth between the vertebrae. The surface area, configuration, orientation, surface texture and deformity characteristics of an interbody spacer or bone graft placed in the disc space can affect the stability of the joint during fusion and thus affect the overall success of a fusion procedure.
Interbody spacers formed of stainless steel, titanium or titanium alloys, porous tantalum, and other biocompatible metal alloys are known. Furthermore, interbody spacers formed of polymeric materials such as polyether ether ketone (PEEK) are also known. With interbody implants made out of metal, the metal prevents adequate radiographic visualization of bone growth through the implant between the vertebrae. Dissimilarly, interbody implants made of a radiolucent material, such as polyetheretherketone (PEEK), may allow post-operative visualization of bone growth or fusion through the implant with an imaging device, such as on an X-ray.
In accordance with the present disclosure, composite implants are disclosed that can be inserted at a fusion site which may provide an osteoconductive scaffold for bony ingrowth while allowing post-operative visualization of bone growth or fusion through the implant using radiographic visualization instrumentation. Methods of manufacturing the composite implants are also disclosed.